Dynamic sonography in the diagnosis of ligament and meniscal injuries of the knee.

A total of 84 patients with ligament or meniscal injuries of the knee was prospectively examined clinically and under anaesthesia, by arthroscopy and sonography. The sensitivity, specificity, positive and negative predictive values were compared. For sonography a high resolution scanner (Picker LSC 7000 with a 5-MHz transducer) was used. The sonographical examination was dynamic under normal and stress conditions. The sensitivity of sonography for diagnosis of rupture of the medial collateral ligament (LCM) was 87%, of the anterior cruciate ligament (LCA), 70% and of menisci, 89% and was thereby similar to that for examination under anaesthesia and arthroscopy and significantly superior to clinical examination alone. The specificity of sonography was very high: for rupture of the LCM 96%, the LCA 98% and the menisci 78%. Only for diagnosis of partial ligament rupture, especially partial LCA rupture, was the sensitivity of sonography low. In diagnosing ligament and meniscal injuries of the knee, sonography should be used routinely as a primary diagnostic tool after clinical examination because: 1. It is inexpensive 2. It has no side effects 3. It helps to cut down X-ray exposure 4. Anaesthesia is not required 5. It allows the recognition and avoidance of muscle tightness 6. Repetitions are possible at will 7. Documentation is included 8. Sensitivity and specificity are very good.